Lady Luck is once again smiling on India's richest and most powerful business houses. In the past six months, the Indian equity market has more than doubled and so has the wealth of India's top promoters. The combined wealth of the country's top-20 promoter families, based on their equity holding, has swelled to Rs 8.43 lakh crore, or $174 billion, as per Thursday's closing price. At the bottom of the bear run in October 2008, their net worth had shrunk to under $79 billion from $244.3 billion at the peak of the bull run on January 10, 2008.

The list continued to be lead by Mukesh Ambani of RIL. The elder Ambani is now worth over $33 billion and has nearly doubled his net worth. However, his wealth is still down 25% from its peak. He is followed by the Tatas and Anil Ambani. While all business houses have been the beneficiaries of a revival in the market, the biggest gainer has been the Munjal family, which owns nearly 29% of Hero Honda, the country's largest two-wheeler maker. The family is now two-and-a-half times richer than it was even at the peak of the bull run in early 2008 and is now India's richest automotive family, ahead of the Mahindras, the Bajajs and the Tatas. This is remarkable, considering the fact that most business houses are still far away from scaling their all-time peaks. The Munjals' success owes to the financial performance of Hero Honda, which defied all odds to report a 34% growth in net profit in FY09 and continues to show a similar momentum in the current financial year too.

Among big business houses, the Tatas, Wipro and the Om Prakash Jindal family have been the biggest beneficiaries of the current bull-run. The Tatas, for instance, have not only recouped their entire losses of 2008, but also are now richer than they were at the peak of the bull run. The combined value of Tata Sons and Tata Industries' equity holding — two key promoter-companies of the Tata group — is now worth Rs 1,23,000 crore compared with around Rs 1,18,000 crore during the peak. It's largely due to the market beating performance of TCS, whose market value has nearly trebled from its 52-week low to around Rs 1,13,000 crore at the end of Thursday's trading. Tata Sons owns a 73.75% stake in TCS. Of late, other major Tata group companies have also began to beat the market.

Azim Premji of Wipro has seen a similar rise in his wealth, thanks to a general revival in the equity market and renewed interest in IT stocks. In the past 11 months, Mr Premji's net worth has nearly tripled to around Rs 66,000 crore from nearly Rs 25,500 in October 2008. Delhi-based Om Prakash Jindal family, which has huge interest in steel, has been even more lucky. The family, which owns some of the largest steel companies in India, including JSW Steel, Jindal Steel & Power and JSL, has seen a six-fold jump in its net worth in the past 11 months. The family's equity holding is now worth Rs 41,500 crore against Rs 37,800 crore at the peak of the bull-run in January 2008.

However, others have not been that lucky. Anil Ambani, for instance, has seen a 75% jump in his net worth, but is still down 53% from the peak. It's the same with the country's two biggest real estate barons — KP Singh of DLF and Chandra's of Unitech.

Our estimate is based on the market value of promoters' stake in various listed group companies. However, to avoid repetition, we have netted the cross-holding across listed companies. For instance, while estimating the Aditya Birla family's net worth, we have netted out the Grasim stake in Hindalco and vice versa.